Abstract:
In design and manufacturing many systems are used to manage technical product data. Each system
has its own data formats so the same information has to be entered multiple times into multiple
systems leading to redundancy and error. Generic format is needed to overcome this
misunderstanding. Geometric models with complete design data details are created through CAD
software and translated into an equivalent boundary representation(B-Rep) format in the form of
neutral file. These neutral files can be transported for further analysis or process planning. Automatic
feature recognition is the process of significant information extraction from neutral file and identifying
the welding features without any human intervention. Automatic feature recognition is an important
aspect for CAPP and it is an important task between CAD and CAPP. CAPP is the bridging gap
between CAD and CAM. Automated feature recognition is considered a critical node for integration of
CAD/CAPP/CAM. Research in feature recognition has received significant attention, however, the
majority of feature recognition systems are for machining features.
Present work is an attempt to develop a method for automatic feature recognition of spot welding from
neutral file, STEP (AP203). which is an international standard for geometric and non-geometric data
transfer between heterogeneous systems. This study explains the software Development in Python
language for feature recognition which work as an integration between CAD and CAPP. The system
developed uses a simplified and generalized methodology of extracting spot welding feature
information from STEP files. Three dimensional Assembly with multiple spots weld created by using
Creo 3.0 software to recognize features. Three main features of Spot welding are highlighted (1) Total
Number of spot welds (2) Coordinates and Diameter of each spot weld (3) plane of weld. Rule based
technique is used for recognizing features. The software has been implemented and tested on several
components. The results are satisfactory and successful. An illustrative case studies is presented to test
and validate the method.
